Cabinet knob



FIG. 1 is a perspective view of a cabinet knob showing my new design;

FIG. 2 is a side elevation view thereof;

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a bottom plan view thereof.

The broken lines shown represent unclaimed subject matter and form no part of the claimed design. 

The ornamental design for a cabinet knob, as shown and described. 